The present invention relates to a power takeoff device for a transmission. More particularly, the present invention relates to a combination power takeoff and gearbox for a transmission for driving auxiliary equipment from the transmission.
Vehicles, such as cars, trucks, SUVs, military vehicles and the like often require auxiliary equipment to be driven to, for example, power a generator, drive a pump (such as a hydraulic pump) or the like. This permits the auxiliary equipment to be used in remote locations without the need for additional or separate drive units or engines.
Known arrangements for providing this auxiliary drive require a combination of a separate power take off and gearbox. The power take off is a unit that is directly driven from the vehicle transmission. The gearbox takes output from the power take off and changes the output speed of the driver unit, for example, an output shaft, to a desired drive speed. In addition, in order to engage and disengage the output shaft from the transmission, a clutch or other device must also be introduced into the system to effect this functionality.
The major drawback to providing an auxiliary power output is the space that is required to accommodate the equipment. A power takeoff that is separate from a gearbox which may be separate from a clutch can subsume valuable space that is need for other components. In fact, the space that is required can result in needed space taken away from other components. In addition to the space needed for these separate components, the added weight of two to three components is also a disadvantage to this arrangement.
Moreover, the known arrangements do not provide for easy selection of gear ratios and output speed (RPM).
Accordingly, there is a need for a combination power takeoff/gearbox that is a single, unitary device. Desirably, such a device is compact and is readily installed and removed from the vehicle. More desirably, such a device can be readily adapted to achieve a desired output speed and/or gear ratio. Most desirably, such a device is engaged and disengaged by an integral clutch assembly. Also most desirably, such a device is configurable for mounting of auxiliary equipment, eliminating the need for additional drive components such as couplings and drive shafts.